Apparatus for injection of liquid

ABSTRACT

A portable apparatus for the slow and continuous injection of liquid for feeding small quantities of liquid over considerable periods of time. The apparatus is generally cylindrical in shape and includes two coaxial casings: an outer transparent casing which is relatively rigid and an inner deformable casing. At its upper end the apparatus is adapted to be connected to a source of compressed gas by means of a auto tire-type valve and at its lower end the outlet flow rate is controlled by a porous plug. A manometric measuring device is arranged in the inner casing which comprises a piston-and-cylinder unit with color bands for indicating the pressure therein.

[ Nov. 26, 1974 4/1966 128/218 R 9/1969 Bierman 128/214 F 12/1969 Jacuzzi 128/214 F 7/1972 Martin 7 /419 ABSTRACT 2 Claims, 1 Drawing Figure Primary E.raminer-Robert B. Reeves Assistant Examiner-Thomas E. Kocovsky Attorney, Agent, or FirmBaldwin, Wight & Brown A portable apparatus for the slow and continuous injection of liquid for feeding small quantities of liquid over considerable periods of time. The apparatus is generally cylindrical in shape and includes two coaxial casings: an outer transparent casing which is relatively rigid and an inner deformable casing. At its upper end the apparatus is adapted to be connected to a source of compressed gas by means of a auto tire-type valve and at its lower end the outlet flow rate is controlled by a porous plug. A manometric measuring device is arranged in the inner casing which comprises a pistonand-cylinder unit with color bands for indicating the pressure therein.

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United States Patent [191 Bessot et a1.

[ APPARATUS FOR INJECTION 0F LIQUID [75] lnventors: Michel Bessot, Saint Christophe;

Claude Delacote, Laxou;

[22] Filed:

Feb. 9, 1973 [21] Appl No.: 331,181

[30] Foreign Application Priority Data Feb. 11, 1972 [52] U.S. Cl........ ZZZ/386.5, 128/214 E, 128/214 F new HMW mQ 18.7 62 A M9 00m 3D m5 (D1 00 m m $0 2 a mn m.n "N mw W M 2 0/ O0 WM mk IF 1 0 M 55 [56] References Cited UNITED STATES PATENTS 2.766.907 10/1956 Wallace.................,.........222/3865 APPARATUS FOR INJECTION OF LIQUID The present invention is related to systems enabling slow and continuous injection of liquid and concerns more particularly, but not exclusively, perfusers, i.e., apparatus for injecting a medicinal substance or blood into an organism or organ, this appears to be the most interesting application.

An object of the present invention is to make such apparatus better fulfill the practical desiderata particularly with respect to convenience in use, reliability and simplicity of construction.

In the prior art a certain number of perfusers are known which are used for chemical therapy the most simple one of which is the conventional drip feed system. Bottles placed sufficiently high above the bed of the patient or under pressure by bubbling a gas therethrough are hooked up to the patient by means of tubes which are long enough so as to give the patient a certain degree of freedom of movement. Such treatment can in some case last for several weeks.

Syringe-type perfusers or electrically operated pumps have the drawback of being powered by an electric current. Such a source of electricity is preferably a fixed supply since the reliability thereof is limited. On the other hand, the equipment is cumbersome and has a considerable weight which makes it unsuitable for being transported.

A new type of perfuser called a chronofuser enables certain of these drawbacks to be overcome by using a clockwork for the drive means. Such an apparatus is nevertheless delicate, expensive, noisy and does not enable intensive use.

The object of the present invention is a perfuser which operates independently, is small in size and weight, sturdy and quiet, simple to maintain and relatively inexpensive.

The apparatus comprises a first casing of flexible material for containing liquid connected to an outlet feed tube through a replaceable porous plug disposed in the path of flow of the liquid, a second casing surrounding the first and provided with means for connecting it to a source of compressed gas in order to create a certain level of pressure therein, manometric measuring means being provided inside the second casing for checking said pressure.

According to a preferred embodiment of the invention, the two casings are cylindrical and coaxial, the first being formed of deformable plastic material and the second being formed of transparent plastic material so that the indications of the manometric measuring means contained in the second casing are viewable.

According to another preferred feature of the invention, the manometric measuring means comprises a piston-and-cylinder unit, wherein the length extending out of the cylinder gives an indication of the pressure.

Other features and advantages of the invention will be brought out in the remainder of the description and the accompanying drawing which are made merely by way of example.

The sole FIGURE of the drawing shows in crosssection an embodiment of the perfuser according to the invention.

In the FIGURE a first tubular casing 1 formed of transparent plastic material is shown. The ends of this casing are closed off by two end portions 2 and 3. A

second casing 4 also of tubular shape is disposed inside the first casing 1 and is adapted to contain the liquid to be injected. The second casing is formed of a plastic material whose walls are sufficiently flexible to enable deformation. The second casing is connected to the end portion 2 by means of a tubular element 5 housed inside the end portion 2 and sealingly joined by stuffing box system. A threaded sleeve 6 enables the scaling function to be effected. The tubular element 5 is effectively extended downwardly by a connecting member 7 having a porous plug 8 arranged inside. This porous material plug interposed in the path of flow of the liquid causes a pressure drop and assures a constant liquid flow rate. The upper end of the casing 4 is closed off by a cylinder 9 disposed inside thereof. A piston 10 is adapted to slide in this cylinder. The upper end of the piston 10 acts as a visual indicator depending on whether a band 11 on the piston p extends beyond the cylinder 9, or not. The band 11 may be red in color for example whereas a band 12 also on the piston is blue and indicates that the pressure is sufficient in the casing 1.

Thus, the different markings on the portion of the piston 10 which projects beyond the open end of the cylinder 9 assist in visually determining the amount of projection of that portion beyond the open end of the cylinder. The upper end portion 3 of the outer casing 1 is provided with an inlet valve 13 to which a source of compressed air may be attached. The valve 13 is preferably an automobile tire-type valve.

The operation of the apparatus is easy to understand.

Once the casing 4 is filled with liquid, the casing 1 is connected to a source of compressed air to produce a particular pressure. When this pressure is great enough, which can be checked by the pressure indicator ll, 12 which is in its low position, the compressed air supply is disconnected and the apparatus is ready to operate. The pressure exerted on the flexible casing 4 causes a slow flow of the liquid through the porous plug 8. It should be noted that the connecting member 7 is replaceable so as to modify the flow rate by changing the plug.

The apparatus is filled by first producing a pressure in the casing in order to compress the casing 4. The air is thereby driven out. The filling per se is then effected by connecting the connecting member 7 to the liquid feed tube and then opening the valve 13. Owing to its elasticity, the casing 4 tends to return to its cylindrical shape. The liquid is drawn in and refills the casing 4. This is of course, carried out with the connecting member removed.

The connecting member is then put back into place and the valve 13 is connected to a source of compressed gas such as a pump. The apparatus is then ready to be used.

It should be noted that in addition to the pressure control possible by watching the position of the bands 11 and 12 extending out of the cylinder 9 it is possible to get an idea of the quantity of liquid remaining in the casing 4. In fact in proportion to the flow of the liquid the casing 4 decreases in volume by collapsing and forming two substantially parallel walls closer and closer together. By watching the casing edgewise through the transparent walls of the casing 1, one can also get an indication of the amount of liquid left.

The apparatus described above provides numerous advantages. It operates independently, is reduced in size and weight, it can be carried in a pocket or secured to the body for example an arm or leg. Further, it comprises no moving parts which makes it free from any operational mishap and renders it absolutely silent in operation. It has a very simple construction, and is simple to operate and very economical.

The apparatus has been described in use as a perfuser but it is obvious that it is capable of many other applications. In particular it could be used for greasing machines and in general for any problem requiring slow, regular injection of a liquid. The invention is of course not limited to the embodiment described and illus* trated which is given merely by way of example.

What is claimed is:

1. Apparatus for slowly injecting a liquid comprising an inner cylinder casing of flexible material for containing the liquid to be injected; a closed transparent outer cylindrical casing surrounding said inner cylindrical casing; means providing restricted egress ofliquid from said inner cylindrical casing including an outlet tube communicating with said inner cylindrical casing and extending through said outer cylindrical casing in sealed relation thereto; means for admitting fluid under pressure into said outer cylindrical casing and outside of said inner cylindrical casing to press upon the latter in a collapsing sense to force liquid from said inner cylindrical casing through said outlet tube; a cylinder fitted within one end of said inner cylindrical casing which is remote from the communication of the latter with said outlet tube, said cylinder having a closed end within said inner cylindrical casing and an open opposite end; and a pressure indicator piston member reciprocable in said cylinder and having a portion projecting beyond said opposite end of the latter, said piston member being movable relatively to said inner cylindrical casing in response to fluid pressure in said outer cylindrical casing, whereby the moved position of said indicator piston member relative to said inner cylindrical casing indicates the fluid pressure acting on said inner cylindrical casing, the pressure indicating position of said indicator piston member being visible through said transparent outer cylindrical casing.

2. Apparatus according to claim 1 in which the portion of said piston projecting beyond said open opposite end of said cylinder is marked differently along said portion to assist in visually determining the amount of projection of said portion beyond said open opposite end. 

1. Apparatus for slowly injecting a liquid comprising an inner cylinder casing of flexible material for containing the liquid to be injected; a closed transparent outer cylindrical casing surrounding said inner cylindrical casing; means providing restricted egress of liquid from said inner cylindrical casing including an outlet tube communicating with said inner cylindrical casing and extending through said outer cylindrical casing in sealed relation thereto; means for admitting fluid under pressure into said outer cylindrical casing and outside of said inner cylindrical casing to press upon the latter in a collapsing sense to force liquid from said inner cylindrical casing through said outlet tube; a cylinder fitted within one end of said inner cylindrical casing which is remote from the communication of the latter with said outlet tube, said cylinder having a closed end within said inner cylindrical casing and an open opposite end; and a pressure indicator piston member reciprocable in said cylinder and having a portion projecting beyond said opposite end of the latter, said piston member being movable relatively to said inner cylindrical casing in response to fluid pressure in said outer cylindrical casing, whereby the moved position of said indicator piston member relative to said inner cylindrical casing indicates the fluid pressure acting on said inner cylindrical casing, the pressure indicating position of said indicator piston member being visible through said transparent outer cylindrical casing.
 2. Apparatus according to claim 1 in which the portion of said piston projecting beyond said open opposite end of said cylinder is marked differently along said portion to assist in visually determining the amount of projection of said portion beyond said open opposite end. 